A shooting has reportedly occurred at a march in Cairo in support of ousted president Mohamed Morsi, as Egypt braces for a day of protests, dubbed the "Friday of Rejection."

BBC News reported that the shooting, which resulted in at least three deaths, occurred at a gathering of supporters who were marching down a location where Morsi is believed to be under house arrest.

The former president's supporters are demanding that he be reinstated as the country's leader, and are protesting against the military's actions to begin rounding up and arresting members of the Muslim Brotherhood, the political party that was behind Morsi's election last year.

The "Friday of Rejection" is apparently being organized by a number of Islamist groups, including members of the Muslim Brotherhood, who have called for a peaceful protest.

Some, however, are calling on extreme actions, Reuters reported, with crowds outside the Rabaa Adaweya mosque in a Cairo chanting "Down, down with military rule!" and "We call for jihad in the whole country." The army has sent extra armored vehicles and set up makeshift barricades in the area where Morsi supporters continue gathering.

In a statement, the National Alliance in Support of Electoral Legitimacy said it affirmed its "full and categorical rejection of the military coup – against the President, the Constitution and democratic legitimacy – and all consequent actions and effects."

Egypt has already chosen a new interim president in the face of Adly Mansour, the chief justice of the Supreme Constitutional Court, who was sworn in on Thursday, a day after the army announced it has suspended the constitution and ousted Morsi as president of Egypt.

Morsi had rejected the 48 hour deadline the military gave him to respond to protests over the weekend where millions of Egyptians took to the streets against his rule, and had made no indication that he was willing to step down.

"The youth had the initiative and the noblest thing about this glorious event is that it was an expression of the nation's conscience and an embodiment of its hopes and ambitions. It was never a movement seeking to realize special demands or personal interests," the interim president said when he was sworn in.

Mansour added that new parliamentary and presidential elections will be held to choose new leaders and a way forward for the African country, though the protests on Friday show that Morsi's supporters are not prepared to give up hopes that the former president might still be reinstated.

USA Today said that at least 50 people have been killed in clashes between Morsi's opponents and supporters over the past week, with incidents being reported in Cairo as well as the former president's hometown of Zagazig.

The Human Rights Watch organization has warned against political arrests, issuing a statement on Thursday that read:

"A return to Mubarak-era practices of mass arrests and politically-motivated imprisonment of Muslim Brotherhood leaders will have the worst possible effect on Egypt's political future."

The statement continued: "Egypt's new interim president and the military leadership should immediately end reprisals against Muslim Brotherhood political leaders, including arrests or travel bans, and should allow the Freedom and Justice Party to fully exercise freedom of association.

"The new government needs to make it clear immediately that it and all state bodies, including the armed forces, will respect all basic rights that apply within Egypt at all times."